Radioactivity of the atmospheric aerosols detected by CTBTO stations in Africa following the accident at the Fukushima Daiichi nuclear power plant

Radionuclides from the reactor accident Fukushima Daiichi nuclear power plant were observed in the airborne aerosols at CTBT International Monitoring System (IMS) stations (MRP43, CMP13) in Africa. The maximum activity concentrations in the air measured in Mauritania were 186.44 10-6 Bq.m-3, 264.16 10-6 Bq.m-3 and 1269.94 10-6 Bq.m-3 for 134Cs, 137Cs and 131I respectively, and in Cameroon 16.42 10-6 Bq.m-3, 25.53 10-6 and 37.58 10-6 Bq.m-3 respectively for 134Cs, 137Cs and 131I. The activity ratio of 134Cs/137Cs is almost constant throughout the period of time relevant to this study due to their long half-lives of 30.2 years for 137Cs and 2.06 years for 134Cs. Whereas the 131I/137Cs activity ratio varies in time according to the radioactive decay with a half-live of 8.06 days for 131I and different removal rates of both radionuclides from the atmosphere during transport. The EMAC atmospheric chemistry-general circulation was used to simulate the emission and transport of the isotope 137Cs and map the deposition of the 137Cs deposition over Africa.

Medical Therapy of Patients Contaminated with Radioactive Cesium or Iodine

Follow-up studies after the Chernobyl and Fukushima accidents have shown that 137Cs and 131I made up the major amount of harmful contaminants in the atmospheric dispersion and fallout. Other potential sources for such radionuclide exposure may be terrorist attacks, e.g., via contamination of drinking water reservoirs. A primary purpose of radionuclide mobilization is to minimize the radiation dose. Rapid initiation of treatment of poisoned patients is imperative after a contaminating event. Internal contamination with radioactive material can expose patients to prolonged radiation, thus leading to short- and long-term clinical consequences. After the patient's emergency conditions are addressed, the treating physicians and assisting experts should assess the amount of radioactive material that has been internalized. This evaluation should include estimation of the radiation dose that is delivered and the specific radionuclides inside the body. These complex assessments warrant the reliance on a multidisciplinary approach that incorporates regional experts in radiation medicine and emergencies. Regional hospitals should have elaborated strategies for the handling of radiation emergencies. If radioactive cesium is a significant pollutant, Prussian blue is the approved antidote for internal detoxification. Upon risks of radioiodine exposure, prophylactic or immediate treatment with potassium iodide tablets is recommended. Chelators developed from calcium salts have been studied for gastrointestinal trapping and enhanced mobilization after strontium exposure.

Tritium and radiocarbon in the western North Pacific waters: post-Fukushima situation

Impact of the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident on tritium (³H) and radiocarbon (¹⁴C) levels in the water column of the western North Pacific Ocean in winter 2012 is evaluated and compared with radiocesium (^134,137Cs) data collected for the same region. Tritium concentrations in surface seawater, varying between 0.4 and 2.0 TU (47.2-236 Bq m^-3), follow the Fukushima radiocesium trend, however, some differences in the vertical profiles were observed, namely in depths of 50-400 m. No correlation was visible in the case of ¹⁴C, whose surface Δ¹⁴C levels raised from negative values (about -40‰) in the northern part of transect, to positive values (∼68‰) near the equator. Homogenously mixed ¹⁴C levels in the subsurface layers were observed at all stations. Sixteen surface (from 30 in total) and 6 water profile (from 7) stations were affected by the Fukushima tritium. Surface and vertical profile data together with the calculated water column inventories indicate that the total amount of the FNPP1-derived tritium deposited to the western North Pacific Ocean was 0.7 ± 0.3 PBq. No clear impact of the Fukushima accident on ¹⁴C levels in the western North Pacific was observed.

Temporal changes in radiocesium contamination derived from the Fukushima Dai-ichi Nuclear Power Plant accident in oceanic zooplankton in the western North Pacific

We investigated temporal changes of the contamination of oceanic zooplankton with radiocesium (¹³⁴Cs and ¹³⁷Cs) derived from the Fukushima Dai-ichi Nuclear Power Plant accident one month to three years after the accident at subarctic and subtropical stations (1900 and 900-1000 km from the plant, respectively) in the western North Pacific. The maximum activity concentrations of ¹³⁷Cs in zooplankton were two orders of magnitude higher than the pre-accident level. In the first four months after the accident, the activity concentrations of radiocesium in subtropical zooplankton decreased rapidly, but no similar change was observed at the subarctic station. The radiocesium derived from atmospheric deposition rapidly decreased as a result of seawater mixing. Thus, most of the subtropical zooplankton (with short lifespans) that had taken up radiocesium just after the accident were probably replaced by newly hatched zooplankton within four months of the accident, whereas subarctic zooplankton (with long lifespans) that were highly contaminated with radiocesium were still alive four months after the accident. By the end of the study, ¹³⁷Cs activity concentrations in subtropical zooplankton were still high, whereas the activity concentrations in subarctic zooplankton had decreased to nearly the pre-accident level. The former concentrations were probably influenced by a secondary supply of radiocesium via advection of subtropical mode water that was highly contaminated with Fukushima-derived radiocesium. Unexpectedly, at the subarctic station, the radiocesium activity concentrations in surface zooplankton were lower than those in subsurface zooplankton, whereas the opposite relationship was observed in surface and subsurface seawater. Because carnivores predominated in the subsurface zooplankton community, we hypothesize that the higher radiocesium activity concentrations in subsurface zooplankton were influenced by bioaccumulation. We conclude that radiocesium activity concentrations in zooplankton are influenced not only by the supply of radiocesium to the environment but also by the characteristics of the zooplankton community.

Polymeric stabilizers for protection of soil and ground against wind and water erosion

The article is devoted to the design, development and application of a new generation of binders for various dispersed systems, including soil, ground, sand, waste rock and others. The binders are formed by interaction of oppositely charged polyelectrolytes, both chemically stable and (bio)degradable. The fundamental aspects of interpolyelectrolyte reactions are discussed; the IPC structure and properties of the resulting interpolyelectrolyte complexes (IPCs) allow considering them as unique and universal binders. Numerous results of laboratory experiments and field trials of the IPC formulations are presented. In particular, large-scale tests have been done in the Chernobyl accident zone where the IPC binders were shown to be effective means to suppress water and wind erosion thereby preventing a spread of radioactive particles (radionuclides) from contaminated sites. Ecologically friendly IPC compositions are described, including those based on commercially available polymers; prospects for improving their efficiency and extending the range of their possible use are discussed.

An overview of current knowledge concerning the health and environmental consequences of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident

Since 2011, the scientific community has worked to identify the exact transport and deposition patterns of radionuclides released from the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in Japan. Nevertheless, there still remain many unknowns concerning the health and environmental impacts of these radionuclides. The present paper reviews the current understanding of the FDNPP accident with respect to interactions of the released radionuclides with the environment and impacts on human and non-human biota. Here, we scrutinize existing literature and combine and interpret observations and modeling assessments derived after Fukushima. Finally, we discuss the behavior and applications of radionuclides that might be used as tracers of environmental processes. This review focuses on (137)Cs and (131)I releases derived from Fukushima. Published estimates suggest total release amounts of 12-36.7PBq of (137)Cs and 150-160PBq of (131)I. Maximum estimated human mortality due to the Fukushima nuclear accident is 10,000 (due to all causes) and the maximum estimates for lifetime cancer mortality and morbidity are 1500 and 1800, respectively. Studies of plants and animals in the forests of Fukushima have recorded a range of physiological, developmental, morphological, and behavioral consequences of exposure to radioactivity. Some of the effects observed in the exposed populations include the following: hematological aberrations in Fukushima monkeys; genetic, developmental and morphological aberrations in a butterfly; declines in abundances of birds, butterflies and cicadas; aberrant growth forms in trees; and morphological abnormalities in aphids. These findings are discussed from the perspective of conservation biology.

Morphological outcomes of gynandromorphism in Lycaeides butterflies (Lepidoptera: Lycaenidae)

The genitalia of male insects have been widely used in taxonomic identification and systematics and are potentially involved in maintaining reproductive isolation between species. Although sexual selection has been invoked to explain patterns of morphological variation in genitalia among populations and species, developmental plasticity in genitalia likely contributes to observed variation but has been rarely examined, particularly in wild populations. Bilateral gynandromorphs are individuals that are genetically male on one side of the midline and genetically female on the other, while mosaic gynandromorphs have only a portion of their body developing as the opposite sex. Gynandromorphs might offer unique insights into developmental plasticity because individuals experience abnormal cellular interactions at the genitalic midline. In this study, we compare the genitalia and wing patterns of gynandromorphic Anna and Melissa blue butterflies, Lycaeides anna (Edwards) (formerly L. idas anna) and L. melissa (Edwards) (Lepidoptera: Lycaenidae), to the morphology of normal individuals from the same populations. Gynandromorph wing markings all fell within the range of variation of normal butterflies; however, a number of genitalic measurements were outliers when compared with normal individuals. From these results, we conclude that the gynandromorphs' genitalia, but not wing patterns, can be abnormal when compared with normal individuals and that the gynandromorphic genitalia do not deviate developmentally in a consistent pattern across individuals. Finally, genetic mechanisms are considered for the development of gynandromorphism in Lycaeides butterflies.

Fukushima nuclear accident: preliminary assessment of the risks to non-human biota

This study assesses the 'radio-ecological' impacts of Fukushima nuclear accident on non-human biota using the ERICA Tool, which adopts an internationally verified methodology. The paper estimates the impacts of the accident on terrestrial and marine biota based on the environmental data reported in literature for Japan, China, South Korea and the USA. Discernible impacts have been detected in the marine biota around Fukushima Daiichi nuclear power plant. This study confirms that the Fukushima accident had caused heavier damage to marine bionts compared with terrestrial flora and fauna, in Japan.

Comment on "radioactive fallout in the United States due to the Fukushima nuclear plant accident" by P. Thakur, S. Ballard and R. Nelson, J. Environ. Monit., 2012, 14, 1317-1324

The May 2012 paper "Radioactive fallout in the United States due to the Fukushima nuclear plant accident" (P. Thakur, S. Ballard and R. Nelson, J. Environ. Monit., 2012, 14, 1317-1324), does not address medical patient excreta as a source of (131)I (t1/2 = 8.04 d) to the environment. While (131)I is generated during fission reactions and may be released to the environment from nuclear power plants, nuclear weapons tests, nuclear fuel reprocessing and weapons production facilities, it is also produced for medical use. Iodine-131 administered to patients, excreted and discharged to sewer systems is readily measureable in sewage and the environment; the patient-to-sewage pathway is the only source of (131)I in many locations.

Fukushima's forgotten radionuclides: a review of the understudied radioactive emissions

In environmental monitoring campaigns for anthropogenic radionuclides released in the course of the Fukushima nuclear accident (2011), most focus had been on gamma-emitting radionuclides. More than 99% of the released activity was due to radionuclides of the elements Kr, Te, I, Xe, and Cs. However, little work had been done on the monitoring of radionuclides other than (131)I, (132)Te, (134)Cs, (136)Cs, and (137)Cs. Radionuclides such as those of less volatile elements (e.g., (89)Sr, (90)Sr, (103)Ru, (106)Ru, plutonium), pure beta-emitters ((3)H, (14)C, (35)S), gaseous radionuclides ((85)Kr, (133)Xe, (135)Xe) or radionuclides with very long half-lives (e.g., (36)Cl, (99)Tc, (129)I, some actinides such as (236)U) have been understudied by comparison. In this review, we summarize previous monitoring work on these "orphan" radionuclides in various environmental media and outline further challenges for future monitoring campaigns. Some of the understudied radionuclides are of radiological concern, others are promising tracers for environmental, geochemical processes such as oceanic mixing. Unfortunately, the shorter-lived nuclides of radioxenon, (103)Ru, (89)Sr and (35)S will no longer exhibit detectable activities in the environment. Activity concentrations of other radionuclides such as tritium, (14)C, or (85)Kr will become blurred in the significant background of previous releases (nuclear explosions and previous accidents). Isotope ratios such as (240)Pu/(239)Pu will allow for the identification of Fukushima plutonium despite the plutonium background.

Comparison of the Chernobyl and Fukushima nuclear accidents: a review of the environmental impacts

The environmental impacts of the nuclear accidents of Chernobyl and Fukushima are compared. In almost every respect, the consequences of the Chernobyl accident clearly exceeded those of the Fukushima accident. In both accidents, most of the radioactivity released was due to volatile radionuclides (noble gases, iodine, cesium, tellurium). However, the amount of refractory elements (including actinides) emitted in the course of the Chernobyl accident was approximately four orders of magnitude higher than during the Fukushima accident. For Chernobyl, a total release of 5,300 PBq (excluding noble gases) has been established as the most cited source term. For Fukushima, we estimated a total source term of 520 (340-800) PBq. In the course of the Fukushima accident, the majority of the radionuclides (more than 80%) was transported offshore and deposited in the Pacific Ocean. Monitoring campaigns after both accidents reveal that the environmental impact of the Chernobyl accident was much greater than of the Fukushima accident. Both the highly contaminated areas and the evacuated areas are smaller around Fukushima and the projected health effects in Japan are significantly lower than after the Chernobyl accident. This is mainly due to the fact that food safety campaigns and evacuations worked quickly and efficiently after the Fukushima accident. In contrast to Chernobyl, no fatalities due to acute radiation effects occurred in Fukushima.

Size distributions of airborne radionuclides from the fukushima nuclear accident at several places in europe

Segregation and radioactive analysis of aerosols according to their aerodynamic size were performed in France, Austria, the Czech Republic, Poland, Germany, and Greece after the arrival of contaminated air masses following the nuclear accident at the Fukushima Dai-ichi nuclear power plant in March 2011. On the whole and regardless of the location, the highest activity levels correspond either to the finest particle fraction or to the upper size class. Regarding anthropogenic radionuclides, the activity median aerodynamic diameter (AMAD) ranged between 0.25 and 0.71 μm for (137)Cs, from 0.17 to 0.69 μm for (134)Cs, and from 0.30 to 0.53 μm for (131)I, thus in the "accumulation mode" of the ambient aerosol (0.1-1 μm). AMAD obtained for the naturally occurring radionuclides (7)Be and (210)Pb ranged from 0.20 to 0.53 μm and 0.29 to 0.52 μm, respectively. Regarding spatial variations, AMADs did not show large differences from place to place compared with what was observed concerning bulk airborne levels registered on the European scale. When air masses arrived in Europe, AMADs for (131)I were about half those for cesium isotopes. Higher AMAD for cesium probably results from higher AMAD observed at the early stage of the accident in Japan. Lower AMAD for (131)I can be explained by the adsorption of gaseous iodine on particles of all sizes met during transport, especially for small particles. Additionally, weathering conditions (rain) encountered during transport and in Europe in March and April contributed to the equilibrium of the gaseous to total (131)I ratio. AMAD slightly increased with time for (131)I whereas a clear decreasing trend was observed with the AMADs for (137)Cs and (134)Cs. On average, the associated geometric standard deviation (GSD) appeared to be higher for iodine than for cesium isotopes. These statements also bear out a gaseous (131)I transfer on ambient particles of a broad size range during transport. Highest weighted activity levels were found on the 0.49-0.95 μm and on the 0.18-0.36 μm size ranges in France and in Poland, respectively. The contribution from resuspension of old deposited (137)Cs was assessed for the coarse particle fractions only for the first sampling week.

Detection and Quantification of Gaseous and Particulate Fukushima Fission Products at Orangeburg, South Carolina

Large amounts of fission products were released from the Fukushima nuclear accident after a devastating earthquake and subsequent tsunami hit the northeast coast of Japan on 11 March 2011. The radioactive mass was sent high into the atmosphere by hydrogen explosions and fires in the reactor buildings at Fukushima Daiichi Nuclear Power Plant and spread all over the world. A relatively complete detection of both gaseous and particulate fission products was conducted during 15 March and 30 May 2011 at Orangeburg, South Carolina, located along the southeast coast of the United States, 11,000 km from the accident site. The histograms of gaseous and particulate radionuclides were obtained, and the major radioactivity plateaus were found between 18 March and 7 April 2011. The maximum levels of particulate and gaseous 131I were 1.0 ± 0.1 and 5.0 ± 0.4 mBq m-3, respectively. The maximum radioactivities of 134Cs and 137Cs were 10 times less than that of the particulate 131I. The average activity ratio of 134Cs to 137Cs was determined as 0.98 ± 0.26 throughout the observation. It was found that the plateaus and spikes in the histogram curves corresponded to the nuclear release events at Fukushima Daiichi. The arrival times of the particulate and gaseous nuclear fallout were determined to be 8 and 10 d, respectively. The deposition rates of gaseous and particulate iodine and the mass transfer between the two phases were discussed based on the radioactivity ratios of the fission products. By comparing with the radionuclide effluent concentrations issued in NRC 10 CFR 20, it was concluded that the Fukushima fallout presented negligible radiation risk to the public at Orangeburg as well as in the southeastern coastal region of the U.S.

Study of indoor radon concentrations and associated health risks in the five districts of Hazara division, Pakistan

A total of 200 indoor air samples were collected to measure radon concentration levels and its contribution to the mean effective doses during different seasons of the period 2009-2010 at different sites of the five districts of Hazara division, Pakistan. The major portion of the region is mountainous and is full of thick forests which receives heavy snow fall in winter. The need for conducting the present survey relied on the fact that occupants spend their lives in poorly ventilated indoor environments of the region, especially in the winter season when they use wood fire inside their residences. The measurements of indoor air samples were taken with RAD-7, a solid state α-detector. Radon concentrations in the whole region range from 41 Bq m(-3) to 254 Bq m(-3) with a geometric mean of 128 Bq m(-3). Radon progenies were measured with a surface barrier detector through alpha spectroscopy from which the Equilibrium Factor (EF) for radon and Radon Decay Products (RDPs) for the smoke-bearing as well as smoke-free indoor environments were deduced. The respective mean values of EF were calculated as 0.49 ± 0.08 and 0.40 ± 0.07. The mean effective doses from indoor air of Abbottabad, Mansehra, Haripur, Battgram and Kohistan districts were calculated as 3.5 ± 1.2, 3.7 ± 0.7, 3.9 ± 1.0, 3.6 ± 1.1 and 3.9 ± 0.7 mSv a(-1) respectively, with the maximum value of 5.1 ± 1.8 mSv a(-1) in Kohistan district during winter and the minimum value of 2.9 ± 1.0 mSv a(-1) in Abbottabad district during summer. The annual exposure dose to the inhabitants of the locality lies below the upper bound of 10 mSv a(-1), as recommended by ICRP-65, and may not pose any significant threat to the public health.